Allelochemical stress induced biochemical changes in the leaves and plant growth regulation in Ricinus communis L

In laboratory experiments the application of Piper betle (L.) leaf extract and eugenol on the castor leaves induced biochemical changes (in protein, phenol compounds, sugars and oxidative enzymes) in the leaves. The plants treated with P. betle leaf extract and eugenol at 20%, 40% and 60% (w/v in acetone) increased the biochemical changes but decreased the enzyme (superoxide dismutase) activity and growth. The allelochemicals application increased the phenolic compounds, protein and sugars contents in treated plants; indicating the changes in metabolism. The allelochemicals at 20, 40 and 60 mg/ml/20 seeds showed considerable impact on shoot growth, which ameliorated with the increasing concentrations.